Well it is something you should exchange your E9 for (noise with volume adjustment) or at least contact FiiO and ask if there is a fix. This is an amp you paid for and it should work perfectly, and FiiO are well known for their customer service, I am sure they will listen.
Re. the T1 - it was listening to the T1 on the E9 that made me buy it - it sounded tremendous and a lot better than it did than on several other more expensive amplifiers. There are always two issues though - the subjective and the objective. Objectively the E9 can power pretty much anything - as Riku said it can power a K1000 in terms of volume. Whether or not you like it's sound is subjective.
It is certainly more impactful and musical in its sound than my Cantate.2, which seems more resolving and refined. The E9 perhaps punches while the Cantate caresses if that metaphor makes any sense. For some people that would swing them towards the Cantate.2, but since I got the E9 that is all I have wanted to listen to because it suits my tastes better for an amp.
So that's what it comes down to - objective - can it power these phones - yes absolutely. Subjective - is it good enough for them - for my tastes absolutely, but others might not agree.
Another point to make is that the difference amps make are HUGELY exaggerated on headfi - a lot of people have spent an obscene amount of money on amps they earnestly want to believe are that much better than entry level amps but in reality we are talking about hundreds of pounds per extra percent performance. I think as long as it isn't trash most amps really sound almost the same.
I want to make that qualification because when I read back my third paragraph it sounds like I'm describing major differences when in reality they are really quite subtle. I think from now on when it comes to amping and daccing of things - I'm going to be very much budget fi - I've heard enough expensive and enough budget amps now to know that going into the high expense territory is really not worth the money. Save it for headphones.